Antenna jacking device



l. L. MARTIN ANTENNA JACKING DEVICE Filed June 16, 1967 Aug. 26, 1969 INVBNTOR.

IVE L.MART|N1 United States Patent 3,463,454 ANTENNA JACKING DEVICE Ive Lee Martin, P.(). Box 2256, Modesto, Calif. 95351 Filed June 16, 1967, Ser. No. 646,608 Int. Cl. B66f 3/24 US. Cl. 254-93 3 Claims ABSTRACT OF THE DISCLOSURE This device is a jack for elevating television antennas to their full height when mounted on a roof or other support, so as to gain full distance television reception. It includes a hollow main jack tubular lower housing with several hollow telescoping elevatable upper jack sections normally retracted inside the lower housing. An antenna clamp is carried by the uppermost jack section for grasping the topmost antenna mast section and holding it until the mast is fully elevated above the roof or support. Compressed air is fed into the main lower jack housing, causing the upper jack sections to be forced upwardly and lifting the antenna mast to its full height. The antenna clamp is constructed for being released upon a pull by a cord dangling to the operator, and an air release valve at the top and bottom jack sections releases the air pressure, allowing the jack sections to be retracted inside the main jack base housing. The jack thus enables one service man to handle the erection and installation of a tall television antenna mast.

This invention relates to improvements in jacking lifting devices and especially those for elevating television and other types of antenna masts into elevated position.

An object of the invention is to provide a novel and improved jacking device which is usable by a single man to elevate and install in operating position an antenna mast for television and other reception.

Another object of the invention is to provide a novel and improved jack device in which there is a main lower housing constructed and arranged for temporary mounting on a roof or other support upon which a television or other antenna mast is to be erected, the lower housing being tubular in construction and being provided with one or more tubular telescopically extensible extension members normally disposed within the lower housing and adapted for receiving compressed fluid such as air from a source, entering the lower housing and forcing the extension members to rise telescopically, the topmost of said extension members being provided with a releasable clamp device for releasably grasping an upper portion of the antenna mast to be erected, so that as the compressed fluid is pumped into the jack device, the antenna mast is elevated with the topmost extension member of the jack device and the antenna is securable in final elevated position the roof or other support, for use; and in which means is provided for easily retracting the jack device after mast erection.

A further object of the invention is to provide a novel and improved antenna jack device for erecting television and other antenna masts, which is simple in design, formed of relatively few parts, inexpensive to manufacture from readily available piping and similar materials, and can be handled by one serviceman if needed.

These and other objects and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention, as illustrated in the accompanying drawings, forming a part hereof, and in which:

FIGURE 1 is an elevational view of an antenna jack device mounted on a roof in retracted position, engaged with an antenna mast to be erected thereby, and indicating in broken lines, the elevated extended positions of the jack device and mast.

FIGURE 2 is a detailed elevational view showing a portion of the jacking device and its locking clamp in clamped locked engagement with the antenna mast in full lines, and shown in unclamped position in broken lines.

FIGURE 3 is a fragmentary left end elevational view of the lower portion of the device of FIGURE 1, and the roof on which it is supported.

In connection with the erection of antenna masts for television receivers and the like, it is important to use as high an antenna elevation as is possible, especially where the television transmitter is at a considerable distance from the receiver, and where intervening obstacles such as hills, buildings, and the like may be in between. Where the antenna mast is of substantial height such as about 30 feet or more, it is difficult for a single service man to handle the installation of the mast alone, and hence additional labor and materials are needed, which not only increases the cost of the installation, but also the time involved. The present invention provides a single and convenient antenna mast jack device to solve these problems, by making it possible for even one man to handle the erection and installation of the antenna mast.

In order to understand clearly the nature of the invention, and the best means for carrying it out, reference may be had to the drawings, in which like numerals denote similar parts throughout the several views.

As shown, there is a roof 10 of a home or other building, upon which a television antenna mast 12 is to be erected. The antenna 12 may be metal construction and has its lower end 14 inserted and secured into a socket in the antenna base bracket or fixture 116, which has two angularly divergent flanges 18 to fit the roof contour and is secured to the roof by screws 20. While one form of such antenna base is shown for example, it is understood that various shapes and constructions of such base 16 may be used, which may be larger or wider or more massive, depending on the size of the antenna mast, roof contour, and other factors. Also, where the antenna is quite high and strong winds may be encountered, guy wires may also be used for further steadying the antenna.

The antenna mast 12 may be all in one single piece, or may be made of several tubular telescoping hollow mast sections, the one of greatest diameter being at the bottom, and the others telescoped successively one within the other. The topmost end 22 of the antenna mast has secured thereto the television antenna indicated generally at 24, the configuration of the antenna itself depending upon the desires of the designer and user, as to omnidirectional pickup from all or a variety of directions, or a highly directional antenna array, such as a Yagi array, which may be permanently directed toward a particular transmitter, or may be rotated by an electrical antenna rotating device mounted at the top of the mast below the antenna array itself.

In order to elevate the antenna mast 12 to its full height, there is provided an antenna mast jack generally indicated at 26. The jack includes a hollow tubular jack base member 28, the lower end of which is secured in a base socket 30 with a jack support 32 in the form of two angularly divergent flanges 34 to fit the roof crown contour. A small portable air compressor 36 may be connected by pipe 38 through valve 40 to the air inlet fitting 42 for conducting compressed air into the lower end of jack base tube 28. Several hollow tubular telescoping jack elevating sections 44 and 46 are normally retracted inside the hollow tubular jack base 28, and as the upper section 44 is closed at the top, it is seen that the compressed air will force the jack sections upwardly 3 as indicated in broken lines in FIGURE 1 to positions such as 44a and 46a.

In order to elevate the antenna mast sections with the jack sections, there is provided a releasable clamp 48 seen in FIGURE 1 and in detail in FIGURE 2. The clamp has a pivot shaft 50 journaled in a bearing formed in the top cap 52 of the topmost jack section 44, and extending rightwardly therefrom as seen in FIGURE 1, with an eccentric cam locking member '54 mounted on the shaft 50 for rotation therewith. A crank arm 56 is secured to the shaft 50 for rotation therewith, so that the deflection of the crank 56 from its full line position to its dotted line position in FIGURE 2 turns the shaft 50 and the cam locking member 54 in a clockwise direction. A pull string or cord 60 hangs from lever arm 56 and is of suflicient length to be within reach of the serviceman on the roof. From FIGURE 2, it is seen that there is also a hemicylindrical bracket 62 carried by the cap 52 and having its open edge 64 sulficiently opened as to allow insertion between it and the locking member 54 of the topmost antenna mast section 22 for being clamped between the member and the interior of the bracket 62. As seen in FIGURE 2, the member 54 is eccentrically mounted on shaft 50 and has a curved hollow contoured groove 66 in its perimeter which is gradually increased in depth. Thus, when the antenna section 22 is in position as seen in FIGURES 1 and 2, and the lever arm 56 is in the full line position shown, the effective diameter of the member 54 is greater and hence there is a good frictional clamping engagement with the antenna mast section 22. When the antenna mast has been upraised to its full height and the various antenna mast sections secured to each other in any suitable manner, then it is only necessary for the Serviceman to pull on cord 60, to move lever 56 to position 56a, reducing the clamping diameter and hence loosening the jack from the mast section 22 and allowing retraction of the jack sections to the full line positions of FIGURE 1.

Having pulled cord 60 to unclamp the clamp 48 from the antenna mast section 22, the installer can merely release the air from the lower jack section 28 by opening valve 40 while shutting off the compressor 36, valve 40 being a three Way valve which can be turned to allow compressed air to enter section 28, or in another position to be fully closed to retain the air in section 28, or in a third or relief position to be open to vent to atmosphere to allow the air to flow out of the jack and allow gravity to pull down the extended jack sections. For faster descent, if desired, another normally closed air relief valve 70 may be positioned at the upper end of the topmost jack section 44, with a pull cord which the serviceman can pull to allow quicker relief of air from the jack. The device may be provided with a switch for shutting off automatically the air compressor 36 when the cord 60 is pulled, but the compressor itself is normally provided with an on-oif switch anyway.

Where the elevation of the antenna mast is not too great, and the installer is working at the elevation of the antenna at 24a on top of a ladder, all the controls may be duplicated at the top levels for easy reach by him, so that cord 60 and valve 44a are within reach. The present device thus provides quick and easy erection of an antenna mast with a minimum of time and at low cost. In addition, the jack device is easily manufactured, and can be carried along on the truck of the installer from job to job.

In order to avoid undue air leakage from the interior of the adjacent extensible jacking sections, it is desirable to provide a form of sealing, such as rubber or rubberlike rings between the end of adjacent jacking sections, with suitable flanges or constrictions to retain the 0 rings in place as the jacking sections are extended or retracted.

A spring 71 is extended around shaft 50 for providing counterclockwise bias to normally keep level 56 in its full line cam engaged position as in FIGURE 2, being anchored suitably.

Although a preferred embodiment of the invention has been described in specific terms it is understood that various changes may be made in size, shape materials and arrangement without departing from the spirit and scope of the invention as claimed.

a What I now claim is:

1. A jacking device for antenna masts and the like,

comprising main housing means constructed and arranged for being engagingly supported upon a roof and the like upon which an antenna mast is to be erected, said main housing means having a main chamber formed therein, extensible jacking section means engaging said main chamber and constructed and arranged for being extended outwardly therefrom to elevate an upper portion of said jacking section means substantially above said main housing means, means for subjecting said main chamber to fluid pressure from a source for acting upon said jacking section means to extend the same out from said main housing means, and clamping means carried by said extensible jacking section means and movable therewith said clamping means being constructed and arranged for releasable engagement with an antenna mast for elevating said antenna mast upon elevation of said jacking section means, said clamping means comprising a shaft journaled in the uppermost of said jacking sections, crank means for rotating said shaft, a curved clamp wall carried by said uppermost jacking section means and defining an antenna mast receiving clamping recess, and cam means carried eccentrically by said shaft and rotatable therewith, so that as said clamping means is rotated in one direction, said antenna mast section is firmly clamped therewith, and when it is turned in the opposite direction said mast section is unclamped therefrom, and a source of compressed fluid for supplying fluid to said jacking section means for elevating the latter.

2. A jacking device according to claim 1, and wherein said main housing means comprises a hollow tubular jacking base member having a bore defining said main chamber, and wherein said extensible jacking section means comprises a plurality of hollow tubular jacking sections telescoped one within the other, with the largest and lowermost thereof telescoped within the said jacking base member so that all are telescoped within said jacking base member when in retracted position, air sealing means for sealing the adjacent surfaces of said telescoping members against leakage of fluid air therebetween upon pressurization of said main chamber, so that upon pressurization of said bore said jacking section means undergo telescopic upright extension.

3. The construction according to claim 2, and comprising compressed air inlet means carried by said jacking base member and iconnectable to said source of compressed fluid for actuating said jacking section means into elevation, normally closed air outlet relief valve means carried by and communicating With the interior of said topmost jacking section means, and constructed and arranged for being remotely actuated to open when the fluid pressure therewithin is to be released to allow said jacking section means to retract telescopically to retracted lowermost positions Within their said base member, said source of compressed air fluid communicating with said air inlet means and operable for filling said base member and said jacking section means, and valve and switch means for halting said operation of said source of compressed fluid remotely and at its location, when the antenna is upraised to its full elevation.

References Cited UNITED STATES PATENTS 3,263,382 8/1966 Tourtellotte 254-133 X 3,279,755 10/1966 Notenboom 25493 3,300,205 1/ 1967 Fitzpatrick 269-236 X ROBERT C. RIORDON, Primary Examiner DAVID R. METTON, Assistant Examiner 

